The reverse vilsmeier approach to the synthesis of quinolines, quinolinium salts and quinolones
摘要:
N-Methylformanilide(MFA) reacts with various electron-rich alkenes in POCl3 solution to give N-methylquinolinium salts generally in good yield. The alkenes can be vinyl acetate, an aldehyde or ketone enamine (preferably the morpholine enamine), a methyl aryl ketone (reacting as its enol) or it may be generated from an alkanoamide bearing alpha-protons (which produces an alpha-chloroenamine in situ). The reaction is effective for a variety of other alkyl-, aryl- and benzyl- formanilides as well as ring substituted anilides though electron-withdrawing groups tend to inhibit cyclisation. The mechanism of the cyclisation has been elucidated and shown to involve an electrocyclic ak process. The reactions of MFA with amides in POCl3 gives 4-quinolones on alkaline workup.
4-Dimethylamino-1-trifluoracetyl-pyridinium-trifluoracetat: Ein effizientes Reagens zur Synthese von Trifluormethyl-1,3-dicarbonyl-Verbindungen
作者:Gerhard Simchen、Andreas Schmidt
DOI:10.1055/s-1997-1501
日期:1997.1
4-Dimethylamino-1-trifluoroacetylpyridinium Trifluoroacetat: An Efficient Reagent for the Preparation of Trifluoromethyl-1,3-Dicarbonyl CompoundsEnamines 2 and O-trimethylsilyl ketene acetals 4 are trifluoroacetylated on reaction with the title reagent to yield trifluoroacetyl enamines 3 and trifluoromethylsilylenol ethers 5, respectively. Trifluoromethyl 1,3-diketones 6 and trifluoromethyl β-keto esters 7 are obtained by hydrolysis of compounds 3 and 5.
Opitz,G.; Griesinger,A., Justus Liebigs Annalen der Chemie, 1963, vol. 665, p. 101 - 113
作者:Opitz,G.、Griesinger,A.
DOI:——
日期:——
Eicher,T.; Born,T., Justus Liebigs Annalen der Chemie, 1972, vol. 762, p. 127 - 153
作者:Eicher,T.、Born,T.
DOI:——
日期:——
VILSMAIER E.; TROEGER W., SYNTHESIS, 1980, NO 6, 466-469
作者:VILSMAIER E.、 TROEGER W.
DOI:——
日期:——
The reverse vilsmeier approach to the synthesis of quinolines, quinolinium salts and quinolones
作者:Otto Meth-Cohn、David L Taylor
DOI:10.1016/0040-4020(95)00729-r
日期:1995.11
N-Methylformanilide(MFA) reacts with various electron-rich alkenes in POCl3 solution to give N-methylquinolinium salts generally in good yield. The alkenes can be vinyl acetate, an aldehyde or ketone enamine (preferably the morpholine enamine), a methyl aryl ketone (reacting as its enol) or it may be generated from an alkanoamide bearing alpha-protons (which produces an alpha-chloroenamine in situ). The reaction is effective for a variety of other alkyl-, aryl- and benzyl- formanilides as well as ring substituted anilides though electron-withdrawing groups tend to inhibit cyclisation. The mechanism of the cyclisation has been elucidated and shown to involve an electrocyclic ak process. The reactions of MFA with amides in POCl3 gives 4-quinolones on alkaline workup.